Studies on the mechanism of control of the methionine biosynthetic enzymes are continuing. The prime emphasis will be on development of controlled in vitro transcription and translation of some of the met genes. We have several transducing phage carrying met genes, all of which will be evaluated. But, in our first experiments we will use a lambda C1857 dmetC phage since we also have a suitably sensitive assay and appropriate bacterial strains carrying deletions of metC and of lac. When we obtain in vitro synthesis of one of the met genes, we will attempt to characterize the regulatory system purifying the repressor and identifying the corepressor. In addition we expect to complete a series of experiments to elucidate the mechanism of derepression of this enzyme during methionine limited growth.